Motor vehicle wheel rims are typically attached to wheel hubs which are either affixed to, part of or adjacent to the brake apparatus, by bolts. The brake apparatus, wheel hub and wheel rim are all configured to rotate about a common axis of rotation, in order to ensure that the respective components are balanced. A centering body, which is aligned coaxially with the axis of rotation, projects outwardly from the wheel hub and is received by an aperture centered in the wheel rim.
The centering bodies of the wheel hubs of motor vehicles vary in diameter, from manufacturer to manufacturer. However, it would be undesirable, both in terms of cost and storage space, for a dealer to stock a different wheel rim to accommodate each separate centering body for each different wheel hub for each manufacturer. Attempts have been made to keep inventory stock of wheel rims low by providing each wheel rim with a common size centering aperture and placing insert rings having different internal borings in the centering aperture of the wheel rim.
Prior art insert rings are known to have several potential drawbacks, however, such as: (1) the insert rings have been difficult to install or remove; (2) the insert rings do not adequately transmit forces from the wheel hub to the wheel rim; and (3) the insert rings are difficult or expensive to manufacture.
An example of a prior art insert ring may be found in German Patent DE-PS 32 33 807. In this reference is disclosed an insert ring which is in the form of a split ring having a gap between the ends of the split. The insert ring is received within an annular groove within the internal bore of the wheel rim. To install the insert ring, it is compressed to fit into the bore and be received in the annular groove where it is allowed to expand to a limited extent, but remains in a somewhat compressed condition.
Such an insert ring requires that a relatively large annular groove be machined or otherwise formed within the internal bore of the wheel rim, which means the manufacturing cost is increased. The insert ring is sensitive to manufacturing errors, such as surface irregularities, which could prevent the insert ring from being fully or uniformly received within the annular groove. The construction of the insert ring as a split ring, to facilitate insertion, requires that the ring have a certain amount of flexibility. In order to withstand the stresses to which the insert ring will be subjected, it should be constructed to be substantially rigid; the split ring construction sacrifices rigidity and introduces instability. The divergent desired characteristics are particularly difficult to meet, with respect to the material and manufacturing processes required. For example, spring steel required for resilience does not machine well. Removal of such a split ring insert ring is difficult. The spaced apart ends of the split ring construction can cause damage to the wheel rim. In addition, the split ring construction makes determination of the sizing of the insert rings difficult, as the uninstalled diameter is different from both the installed diameter and the diameter of the compressed ring during installation.
Another prior art insert ring is disclosed in Japanese Utility Model Number 1864818. The insert ring includes a large radially extending flange portion which extends perpendicular to the axis of rotation of the wheel and adds considerable mass to the wheel. Screws are used for attachment of the insert ring to a disc portion which, in turn, bolts to the wheel rim. The numerous bolt and screw holes tend to weaken the structure of the wheel rim. In addition, the screws must be made of steel for strength, and if the wheel rim is manufactured from aluminum, an electrical cell/circuit is created, with its known destructive characteristics. Still further, the installation or removal of the insert ring of the Japanese Utility Model Number 1864818, requires the tightening or loosening of numerous screws. In addition, the use of screws to affix an insert ring does not permit accurate centering when the screws are tightened, since because of the clearances provided in the screw holes, the threading does not provide a centering force on the screws, and, in turn, the insert ring.
A further prior art insert ring, is disclosed in Japanese Utility Model Number 1876452. Insert ring (1) is configured as a simple smooth-surfaced cylindrical annular ring, having a radially inwardly directed bevel. Such a configuration has the drawback of being permitted to move axially, and relies strictly on its extremely close tolerance fit with the centering body for its operation.
It is an object of the invention to provide a motor vehicle wheel rim assembly, in which an insert ring is provided to permit a wheel rim having a fixed predetermined internal bore to be fitted onto vehicle wheel hubs having centering bodies of different external diameters, in which the insert ring is a solid, continuous and unbroken toroidal body.
It is a further object of the invention to provide a wheel rim assembly which provides for the secure mounting and facilitated removal of the insert ring within the internal bore of the wheel rim.
Still another object of the invention is to provide a wheel rim assembly utilizing an insert ring, having a simplified and more economical construction.
Yet another object of the invention is to provide a wheel rim assembly which uses an insert ring which is of compact size and low mass, for improved performance of the overall wheel rim.
An additional object of the invention is to provide a wheel rim assembly having an insert ring which is advantageously configured to provide improved transfer of forces from the wheel rim to the wheel hub.
These and other objects of the invention will become apparent in light of the present specification, claims and drawings.